- Position a rack in the center of the oven and preheat to 275° F. Put the pecans in a 9 x 13” sheet or roasting pan and shake the pan to level them. Cut the butter into teaspoon-sized bits and scatter it over the pecans.
- Roast in the center of the oven until the butter is melted, about 5 minutes. Take them out and toss until the pecans are glossy and well coated, then roast 45 minutes longer, or until they’re just a shade darker than when they were raw. The pecans continue to cook after they come out of the oven, so don’t let them get too dark. To test them for doneness, cool a pecan slightly and break it in half. The center should be distinctly beige but not dark tan.
- While the pecans are hot, sprinkle on the rosemary and salt them generously. Toss until they are well coated. Serve warm or at room temperature (they’re best warm). Once completely cooled, store them in an airtight tin box or plastic container.